An integrated circuit may contain an extended drain metal oxide semiconductor (MOS) transistor with a drift region in the drain region adjacent to the channel region, such as a laterally diffused metal oxide semiconductor (LDMOS) transistor, a double-diffused metal oxide semiconductor (DMOS) transistor or a drain extended metal oxide semiconductor (DEMOS) transistor. Generally, an average doping in the drift region is less than half an average doping density in the source region of the MOS transistor. An extended drain MOS transistor with the drift region covered by a gate extension field plate, sometimes referred to as a field gap MOS transistor, may exhibit a breakdown voltage above 10 volts, but may have an undesirably large resistance in the drain due to a field oxide element in the drain to terminate the field plate. An extended drain MOS transistor with no field plate over the drift region, sometimes referred to as an active gap MOS transistor, may undesirably exhibit a breakdown voltage below 10 volts and degraded reliability due to hot carrier generation at an edge of the gate.